All 13 areas of the UK struggled to generate new members, and not one region managed to record any growth in new membership.

While inner London managed to remain steady, Northern Ireland and the West Midlands were the regions throwing in the towel - membership declined by 7.6% and 6.5% respectively in those areas.

Mr Balcome also warned clubs would have to act fast to halt the decline in membership as profit margins in the industry are under pressure.

Spending crunch

While lowering joining fees may attract new members, it will not help existing members who are looking to tighten their purse strings, he warned.

"The industry needs to react quickly, as, despite heightened awareness of obesity problems and the link between health and fitness, consumers are not yet opting to join health clubs, and clubs are not achieving expected growth in member numbers," Mr Balcome said.

A previous Deloitte survey said that if more of the population exercised regularly, the economy would benefit from increased gym fees, as well as lower costs to business through fewer sick days.

Meanwhile, lower sickness levels would lead to fewer doctors visits and so lower NHS costs.

The latest Deloitte survey comes as government research has predicted more than 12 million adults and one million children will be obese by 2010 if no action is taken.

The Deloitte survey only tracked the performance of the UK's health club industry - covering 1.4 million members of 470 health clubs including the chains Fitness First and Holmes Place - and did not include public facilities.

Also, it did not reveal whether more consumers were choosing the cheap option of exercising at home or heading out for a jog.